1. Field of the Invention
This invention relates to an adaptive point to multipoint wireless communication system.
2. Related Art
Wireless communication between a sender and a receiver includes sending information using a wireless communication link, in which the sender modulates information onto a wireless communication channel (such as a frequency band reserved for wireless communication between the sender and the receiver), and the receiver demodulates that information from the wireless communication channel, so as to recover the original information.
One problem with known systems is that physical characteristics of the communication link between the sender and receiver can change substantially over relatively short periods of time (for example, the distance between the sender and receiver or the equipment used by the sender or receiver). This is particularly so for interference, such as co-channel interference (CCI), and for multipoint effects, such as reflections resulting in intrasymbol interference and intersymbol interference. Moreover, these physical characteristics can change independently of one another. As a result, selection of a single set of such physical characteristics can result in relatively ineffective or inefficient communication between the sender and the receiver.
Accordingly, it would be advantageous to provide a technique for adaptive point to multipoint wireless communication, in which characteristics of the communication techniques between sender and receiver can be changed adaptively in response to changes in the characteristics of the physical communication media, that is not subject to drawbacks of the known art.
The invention provides a method and system for adaptive point to multipoint wireless communication. In a preferred embodiment, the wireless physical layer and the wireless media-access-control (MAC) layer collectively include a set of parameters, which are adaptively modified by a base station controller for communication with a plurality of customer premises equipment. In a first aspect of the invention, the wireless transport layer includes a number of provisions, such as adaptive link layer transport services and an advanced TDMA (time division multiple access) protocol. In a second aspect, the base station controller adjusts communication with each customer premises equipment individually and adaptively in response to changes in characteristics of communication, including physical characteristics, amount of communication traffic, and nature of application for the communication traffic. The use of point-to-point multipoint wireless channel provides services over a link whose parameters are continuously adapting to current conditions, on a per-user basis.
The invention provides an enabling technology for a wide variety of applications for communication, so as to obtain substantial advantages and capabilities that are novel and non-obvious in view of the known art. Examples described below primarily relate to a wireless communication system, but the invention is broadly applicable to many different types of communication in which characteristics of the communication link are subject to change.